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    <title>Document</title>
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        ctx.arc(100, 100, 100, 0, Math.PI*2);
        ctx.stroke(); // 画个头
        ctx.beginPath();
        ctx.arc(60, 70, 20, 0, Math.PI*2);
        ctx.stroke(); // 画个左眼
        ctx.beginPath();
        ctx.arc(140, 70, 20, 0, Math.PI*2);
        ctx.stroke(); // 画个右眼
        ctx.beginPath();
        ctx.arc(100, 100, 60, 0, Math.PI);
        ctx.stroke(); // 画个嘴
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